Render an animation with 2 different cameras but at the same time
Copy your scene and render both scenes. To do so go to the top of your window and click the + next to your scene and choose Link Objects. 

Next select the inactive camera and make it active. 

Then go to compositing and check Use Nodes. Now delete the Composite node and add another Render Layer node (Add > Input > Render Layer).

Select the newly created scene in the new Render Layer node. 

Now add two File Output nodes (Add > Output > File Output), and input each of the renderlayer nodes into an output node. 

Lastly, in each of the output nodes, navigate to the paths that you want each camera location to be saved to. But be careful not to choose the same path for both nodes, because one output will overwrite the other.

All that's left is to hit render animation and watch the magic happen.